use std::io::prelude::*;
use std::io::Cursor;
use jxl_bitstream::Bitstream;
use crate::{Error, Result};
pub fn read_icc(bitstream: &mut Bitstream) -> Result<Vec<u8>> {
let enc_size = bitstream.read_u64()?;
tracing::trace!(enc_size);
if enc_size > (1 << 28) {
return Err(
jxl_bitstream::Error::ProfileConformance("Too large encoded ICC profile").into(),
);
}
let mut decoder = jxl_coding::Decoder::parse(bitstream, 41)?;
let max_size_header_len = enc_size.min(18) as usize;
let mut encoded_icc = vec![0u8; max_size_header_len];
let mut b1 = 0u8;
let mut b2 = 0u8;
decoder.begin(bitstream)?;
for (idx, b) in encoded_icc.iter_mut().enumerate() {
let sym = decoder.read_varint(bitstream, get_icc_ctx(idx, b1, b2))?;
if sym >= 256 {
return Err(Error::InvalidIccStream("decoded value out of range"));
}
*b = sym as u8;
b2 = b1;
b1 = *b;
}
let mut tmp_cursor = Cursor::new(&*encoded_icc);
let output_size = varint(&mut tmp_cursor)?;
let commands_size = varint(&mut tmp_cursor)?;
let stream_offset = tmp_cursor.position();
tracing::trace!(
enc_size,
output_size,
commands_size,
stream_offset,
"Quick ICC validity check",
);
if stream_offset + commands_size > enc_size {
return Err(Error::InvalidIccStream("invalid commands_size"));
}
if output_size > (1 << 28) {
return Err(jxl_bitstream::Error::ProfileConformance("ICC output_size too large").into());
}
if output_size + 65536 < enc_size {
return Err(Error::InvalidIccStream(
"reported output_size is far smaller than enc_size",
));
}
encoded_icc.resize(enc_size as usize, 0);
for (idx, b) in encoded_icc.iter_mut().enumerate().skip(max_size_header_len) {
let sym = decoder.read_varint(bitstream, get_icc_ctx(idx, b1, b2))?;
if sym >= 256 {
return Err(Error::InvalidIccStream("decoded value out of range"));
}
*b = sym as u8;
b2 = b1;
b1 = *b;
}
decoder.finalize()?;
Ok(encoded_icc)
}
fn get_icc_ctx(idx: usize, b1: u8, b2: u8) -> u32 {
if idx <= 128 {
return 0;
}
let p1 = match b1 {
b'a'..=b'z' | b'A'..=b'Z' => 0,
b'0'..=b'9' | b'.' | b',' => 1,
0..=1 => 2 + b1 as u32,
2..=15 => 4,
241..=254 => 5,
255 => 6,
_ => 7,
};
let p2 = match b2 {
b'a'..=b'z' | b'A'..=b'Z' => 0,
b'0'..=b'9' | b'.' | b',' => 1,
0..=15 => 2,
241..=255 => 3,
_ => 4,
};
1 + p1 + 8 * p2
}
fn varint(stream: &mut Cursor<&[u8]>) -> Result<u64> {
let mut value = 0u64;
let mut shift = 0;
let mut b = 0;
while shift < 63 {
stream
.read_exact(std::slice::from_mut(&mut b))
.map_err(|_| Error::InvalidIccStream("stream is too short"))?;
value |= ((b & 0x7f) as u64) << shift;
if b & 0x80 == 0 {
break;
}
shift += 7;
}
Ok(value)
}
fn predict_header(idx: usize, output_size: u32, header: &[u8]) -> u8 {
match idx {
0..=3 => output_size.to_be_bytes()[idx],
8 => 4,
12..=23 => b"mntrRGB XYZ "[idx - 12],
36..=39 => b"acsp"[idx - 36],
41 | 42 if header[40] == b'A' => b'P',
43 if header[40] == b'A' => b'L',
41 if header[40] == b'M' => b'S',
42 if header[40] == b'M' => b'F',
43 if header[40] == b'M' => b'T',
42 if header[40] == b'S' && header[41] == b'G' => b'I',
43 if header[40] == b'S' && header[41] == b'G' => b' ',
42 if header[40] == b'S' && header[41] == b'U' => b'N',
43 if header[40] == b'S' && header[41] == b'U' => b'W',
70 => 246,
71 => 214,
73 => 1,
78 => 211,
79 => 45,
80..=83 => header[4 + idx - 80],
_ => 0,
}
}
fn shuffle2(bytes: &[u8]) -> Vec<u8> {
let len = bytes.len();
let mut out = Vec::with_capacity(bytes.len());
let height = len / 2;
let odd = len % 2;
for idx in 0..height {
out.push(bytes[idx]);
out.push(bytes[idx + height + odd]);
}
if odd != 0 {
out.push(bytes[height]);
}
out
}
fn shuffle4(bytes: &[u8]) -> Vec<u8> {
let len = bytes.len();
let mut out = Vec::with_capacity(bytes.len());
let step = len / 4;
let wide_count = len % 4;
for idx in 0..step {
let mut base = idx;
for _ in 0..wide_count {
out.push(bytes[base]);
base += step + 1;
}
for _ in wide_count..4 {
out.push(bytes[base]);
base += step;
}
}
for idx in 1..=wide_count {
out.push(bytes[(step + 1) * idx - 1]);
}
out
}
pub fn decode_icc(stream: &[u8]) -> Result<Vec<u8>> {
use std::num::Wrapping;
const COMMON_TAGS: [&[u8]; 19] = [
b"rTRC", b"rXYZ", b"cprt", b"wtpt", b"bkpt", b"rXYZ", b"gXYZ", b"bXYZ", b"kXYZ", b"rTRC",
b"gTRC", b"bTRC", b"kTRC", b"chad", b"desc", b"chrm", b"dmnd", b"dmdd", b"lumi",
];
const COMMON_DATA: [&[u8]; 8] = [
b"XYZ ", b"desc", b"text", b"mluc", b"para", b"curv", b"sf32", b"gbd ",
];
let mut tmp_cursor = Cursor::new(stream);
let output_size = varint(&mut tmp_cursor)?;
let commands_size = varint(&mut tmp_cursor)?;
let stream_offset = tmp_cursor.position();
if stream_offset + commands_size > stream.len() as u64 {
return Err(Error::InvalidIccStream("invalid commands_size"));
}
if output_size > (1 << 28) {
return Err(jxl_bitstream::Error::ProfileConformance("ICC output_size too large").into());
}
let (commands, data) = stream[stream_offset as usize..].split_at(commands_size as usize);
let header_size = output_size.min(128) as usize;
if data.len() < header_size {
return Err(Error::InvalidIccStream("invalid output_size"));
}
let (header_data, mut data) = data.split_at(header_size);
let mut commands_stream = Cursor::new(commands);
let mut out = Vec::with_capacity(output_size as usize);
for (idx, &e) in header_data.iter().enumerate() {
let p = predict_header(idx, output_size as u32, header_data);
out.push(p.wrapping_add(e));
}
if output_size <= 128 {
return Ok(out);
}
let v = varint(&mut commands_stream)?;
if let Some(num_tags) = v.checked_sub(1) {
if (output_size - 128) / 12 < num_tags {
return Err(Error::InvalidIccStream("num_tags too large"));
}
let num_tags = num_tags as u32;
out.extend_from_slice(&num_tags.to_be_bytes());
let mut prev_tagstart = num_tags * 12 + 128;
let mut prev_tagsize = 0u32;
loop {
let mut command = 0u8;
if commands_stream
.read_exact(std::slice::from_mut(&mut command))
.is_err()
{
return Ok(out);
}
let tagcode = command & 63;
let tag = match tagcode {
0 => break,
1 => {
if data.len() < 4 {
return Err(Error::InvalidIccStream("unexpected end of data stream"));
}
let (tag, next_data) = data.split_at(4);
data = next_data;
tag
}
2..=20 => COMMON_TAGS[(tagcode - 2) as usize],
_ => return Err(Error::InvalidIccStream("invalid tagcode")),
};
let tagstart = if command & 64 == 0 {
prev_tagstart + prev_tagsize
} else {
varint(&mut commands_stream)? as u32
};
let tagsize = match tag {
_ if command & 128 != 0 => varint(&mut commands_stream)? as u32,
b"rXYZ" | b"gXYZ" | b"bXYZ" | b"kXYZ" | b"wtpt" | b"bkpt" | b"lumi" => 20,
_ => prev_tagsize,
};
if (tagstart as u64 + tagsize as u64) > output_size {
return Err(Error::InvalidIccStream("ICC profile size mismatch"));
}
prev_tagstart = tagstart;
prev_tagsize = tagsize;
out.extend_from_slice(tag);
out.extend_from_slice(&tagstart.to_be_bytes());
out.extend_from_slice(&tagsize.to_be_bytes());
if tagcode == 2 {
out.extend_from_slice(b"gTRC");
out.extend_from_slice(&tagstart.to_be_bytes());
out.extend_from_slice(&tagsize.to_be_bytes());
out.extend_from_slice(b"bTRC");
out.extend_from_slice(&tagstart.to_be_bytes());
out.extend_from_slice(&tagsize.to_be_bytes());
} else if tagcode == 3 {
out.extend_from_slice(b"gXYZ");
out.extend_from_slice(&(tagstart + tagsize).to_be_bytes());
out.extend_from_slice(&tagsize.to_be_bytes());
out.extend_from_slice(b"bXYZ");
out.extend_from_slice(&(tagstart + tagsize * 2).to_be_bytes());
out.extend_from_slice(&tagsize.to_be_bytes());
}
}
}
let mut command = 0u8;
while commands_stream
.read_exact(std::slice::from_mut(&mut command))
.is_ok()
{
match command {
1 => {
let num = varint(&mut commands_stream)? as usize;
if num > data.len() {
return Err(Error::InvalidIccStream("stream is too short"));
}
let (bytes, next_data) = data.split_at(num);
data = next_data;
out.extend_from_slice(bytes);
}
2 | 3 => {
let num = varint(&mut commands_stream)? as usize;
if num > data.len() {
return Err(Error::InvalidIccStream("stream is too short"));
}
let (bytes, next_data) = data.split_at(num);
data = next_data;
let bytes = if command == 2 {
shuffle2(bytes)
} else {
shuffle4(bytes)
};
out.extend_from_slice(&bytes);
}
4 => {
let mut flags = 0u8;
commands_stream
.read_exact(std::slice::from_mut(&mut flags))
.map_err(|_| Error::InvalidIccStream("stream is too short"))?;
let width = ((flags & 3) + 1) as usize;
let order = (flags >> 2) & 3;
if width == 3 || order == 3 {
return Err(Error::InvalidIccStream("width == 3 || order == 3"));
}
let stride = if (flags & 16) == 0 {
width
} else {
let stride = varint(&mut commands_stream)? as usize;
if stride < width {
return Err(Error::InvalidIccStream("stride < width"));
}
stride
};
if stride.saturating_mul(4) >= out.len() {
return Err(Error::InvalidIccStream("stride * 4 >= out.len()"));
}
let num = varint(&mut commands_stream)? as usize;
if data.len() < num {
return Err(Error::InvalidIccStream("stream is too short"));
}
let (bytes, next_data) = data.split_at(num);
data = next_data;
let shuffled;
let bytes = match width {
1 => bytes,
2 => {
shuffled = shuffle2(bytes);
&shuffled
}
4 => {
shuffled = shuffle4(bytes);
&shuffled
}
_ => unreachable!(),
};
for i in (0..num).step_by(width) {
let mut prev = [Wrapping(0u32); 3];
for (j, p) in prev[..=order as usize].iter_mut().enumerate() {
let offset = out.len() - stride * (j + 1);
let mut bytes = [0u8; 4];
bytes[(4 - width)..].copy_from_slice(&out[offset..][..width]);
p.0 = u32::from_be_bytes(bytes);
}
let p = match order {
0 => prev[0],
1 => Wrapping(2) * prev[0] - prev[1],
2 => Wrapping(3) * (prev[0] - prev[1]) + prev[2],
_ => unreachable!(),
};
for j in 0..width.min(num - i) {
let val = Wrapping(bytes[i + j] as u32) + (p >> (8 * (width - 1 - j)));
out.push(val.0 as u8);
}
}
}
10 => {
if data.len() < 12 {
return Err(Error::InvalidIccStream("stream is too short"));
}
out.extend_from_slice(&[b'X', b'Y', b'Z', b' ', 0, 0, 0, 0]);
let (bytes, next_data) = data.split_at(12);
data = next_data;
out.extend_from_slice(bytes);
}
16..=23 => {
out.extend_from_slice(COMMON_DATA[command as usize - 16]);
out.extend_from_slice(&[0, 0, 0, 0]);
}
_ => {
return Err(Error::InvalidIccStream("invalid command"));
}
}
}
if out.len() != output_size as usize {
return Err(Error::InvalidIccStream("decoded ICC profile size mismatch"));
}
Ok(out)
}